Process and apparatus for applying liquid in a discontinuous manner to a substrate



H. E. POHL ETAL PROCESS AND APPARATUS FOR APPLYING LIQUID Dec. 20, 1966IN A DISGONTINUOUS MANNER TO A SUBSTRATE Filed May 25, 1963 INVENTORSCLAYTON E. WORKMAN HAROLD E. POHL BY ATTORNEY United States Patent OPROCESS AND APPARATUS FUR APPLYING LIQUID IN A DISCBNTINUOUS MANNER T ASUBSTRATE Harold E. Pohl, Kankakee, IlL, and Clayton E. Workman,Minneapolis, Minn., assignors to General Mills, Inc, a corporation ofDelaware Filed May 23, 1963, Ser. No. 282,757 17 Claims. (Cl. 11'745)This invention relates to a method and apparatus for applying in adiscontinuous manner a liquid material to a base member to form thereona desired decorative pattern, and more particularly to such a method andapparatus adapted to accomplish such a discontinuous application as oneof the steps in a process disclosed in a copending US. patentapplication, Serial No. 193,846, filed May 10, 1962, now Patent No.3,219,735, entitled Process for Producing a Decorative Coating andProducts Produced by Said Process, of which the applicants herein areamong the co-inventors.

With the process disclosed in this copending US. patent application, itis possible to produce a decorative coating which closely simulatespolished surfaces of natural stone formations such as m arble, granite,etc., or surfaces of members which are made with natural stone, such asTerrazzo. The manner in which this is accomplished is that a base coatof a suitable resinous liquid material of a desired shade and color isapplied uniformly over a surface of a substrate (i.e. a panel, such as apiece of plasterboard or beaver-board, pressed wood, fiber glass, metaletc.). After this base coating has polymerized or set for apredetermined length of time so that a break able or friable film hasformed over the surface of the base coat, there is a subsequentapplication of a material similar to that which comprises the base coatbut distinguishable therefrom in color and/or shade.

This second application of material is made in a discontinuous andrandom manner and with a moderate impact onto the base coat. It isbelieved that the effect of this is that various concentrations ofmaterial of this second application break through the film which hasformed on the base coat and actually flow or spread outwardly to amoderate extent to form puddles, the peripheral portions of which extendbeneath the base coat (i.e. between the base coat and the panel). Afterthis discontinuous and random application of the second coat, the panelis either tilted or moved laterally to cause those portions of the basecoat which overlap the peripheral portions of the second layerconcentrations or puddles to break loose and slide over the secondlayer. The effect is to create a number of flakes of the base coatmaterial which flakes are themselves spread in a somewhat random patternover the various localized background areas formed by the concentrationsof the material of the second discontinuous application. The panel isthen allowed to stand so that the coatings can set up and harden.

When this process is used to make decorative panels for Walls, floors,and the like, to produce a proper esthetic effect and yet torealistically simulate panels made from natural stone, it is desirableto obtain some general uni formity or overall pattern for a particulargroup of panels, and yet to have each panel or portion thereof bedistinctive within the limits of this general pattern. One reason forthis is that natural stone is usually cut in successive layers or slabs,which, because of their proximity in the natural formation will besomewhat similar in overall pattern but will have individual variations.There is also the practical consideration that a user of these panels(e.g. a customer who is selecting a type of panel by sample) woulddesire the particular panels which he or she buys to be of a distinctivedesign and yet have the panels conform to some overall esthetic standardor pattern.

Thus it is an object to provide a method and apparatus to apply a liquidto a substrate member in a discontinuous and random manner, and yet in amanner which conforms generally to an overall pattern, so that Whileeach application results in a truly distinctive design, there isconformity to a general esthetic standard or pattern.

It is also an object to provide such a method and apparatus which isespecially adapted for use inthe aforementioned process described insaid pending US. patent application (i.e. Serial No. 193,846), nowPatent No. 3,219,735 which method and apparatus, while accomplishing thefirst named object, facilitate the practice of said above-mentionedprocess in creating a coating which realistically simulates a polishedsurface comprised of natural stone, and which conforms to a highesthetic standard.

It is yet another object to provide such a method and apparatus in whichsaid random and discontinuous application of material can readily beaccomplished with a multi colored liquid application, and in which theaims of both the afore-mentioned objects can be accomplished along withsuch multi-colored application.

It is a further object to provide a simple apparatus, which, whileaccomplishing the afore-mentioned objects, is capable of adjustmentand/or rearrangement so that a great variety of truly distinctivepatterns can easily be produced by this apparatus.

These and other objects and features of the invention will be morereadily understood and appreciated from the following detaileddescription of the preferred embodiment thereof selected for purposes ofillustration and shown in the accompanying drawing, in which:

FIGURE 1 is a perspective view of the applicator portion of an apparatusembodying preferred teachings of our invention, and

FIGURE 2 is a side elevational view, partly in section, of saidapparatus.

In the accompanying drawing, numeral 11) designates generally a conveyorupon which a succession of panels 12 are carried along a predeterminedcourse. As shown herein, this conveyor comprises an endless belt 14having drive and idler rollers 16 and 18, respectively.

At the forward end of the belt 12 is a suitable means to apply to theupper surface of each of the panels 12 riding on the belt 14 a base coatof a suitable resinous liquid (as described in the afore-mentionedcopending United States patent application). Such applicating means isshown schematically as a spray applicator 20 located above the belt 14.It is to be understood, however, that any suitable applicating means maybe empioyed by which such a base coat is applied uniformly over asubstrate member.

As the various panels 12 are carried by the belt 14 at a predeterminedrate of travel rearwardly from the spray applicator 20, the freshlyapplied base coat begins to set" so as to form the afore-describedfriable film thereon. At the location along the conveyor 10 where eachportion of the base coat applied to the panels 12 has set for thedesired length of time, there is positioned an apparatus, generallydesignated 22, by which a second application of a suitable resinousliquid (as described in the aforementioned copending United Statespatent application) is made in a discontinuous manner onto the uppersurface of the panel 12.

This apparatus 22 comprises a support frame 23, on which is mounted aplurality (three herein) of parallel and adjacent dispensing troughs24a, b, and arranged to eifect a series flow of liquid of various shadesand/ or colors onto a discharge apron 26, from which the liquid dropsonto the panels 12 passing beneath. At the discharge edge 28 of theapron 26 is a damming spindle, which functions to intermittently blockliquid flow over the apron 26 at various predetermined time intervalsand at various predetermined locations along the apron 26.

Each of the troughs 24a, [9 and 0, comprising front, rear, bottom andside walls 32, 34, 36 and 38, respectively, is located moderately above,and extends transversely of, the conveyor belt 14, and is arranged toextend a slight distance beyond each of the side edges of the panels 12passing therebeneath. There is provided for each trough 24a, b, and c arelated pump 40a, b, and c, respectively, from which the afore-describedliquid material of a particular shade and/or color is supplied to itsrelated trough through a related feed pipe 42 at an accuratelypredetermined rate. The top edge 44a, 1), and c of the front wall 32 ofeach trough 24a, b, or c is moderately lower than the upper edge of itsrelated rear and side walls 34 and 38, so that each front wall 32 actsas a weir over which the liquid from its related pump 46a, 12, or cflows at a predetermined rate. One of the troughs 24c is shown herein asbeing mounted (as at 43) to the frame 23 for swing motion about an axisparallel to its own length, and for limited vertical motion along withsaid swing motion to maintain the proper position relative to the trough24b. Thus by slowly rotating trough 240 during the coating process, theflow therefrom may be varied, without need of changing the rate offlowfrom its related pump 400. The other troughs 24b and 24a may also beswing mounted either as a unit with trough 240 or individually.

Just below the top edge 44b and c of each of the middle and rear troughs24b and c is a related one of two narrow moderately sloping drip aprons45b and 0, respectively. The troughs 24a, 12, and c are so arranged thateach of the drip aprons 45b and c of the middle and rear troughs 24b andc overhangs the rear wall 34 of the trough immediately in front (i.e.24a and b, respectively), with the discharge edge of each drip apron 45band 0 being about one inch (1") above the surface of the liquid in thetrough 24a, or b in front. Thus fluid pumped into the rear trough 240from its related pump 40c flows over its front wall 32 onto its apron45c and into the middle trough 24b, and along with the liquid pumpedinto the middle trough 24b flows into the front trough 24a. Extendingforwardly with a moderate downward slope (i.e. about 20 from thehorizontal) from the front top edge 44a of the front trough 24a is theaforementioned discharge apron 26, which likewise extends transverselyof the belt 14 and extends moderately beyond each side edge of the panel12 passing therebeneath. Thus liquid from the three troughs 24a, b, c,flows onto and down the apron 26 and over the front discharge edge 28thereof to drop onto the panel 12 below.

The afore-mentioned damming spindle comprises a drive shaft 46 mountedparallel to, above, and moderately in front of the discharge edge 28 ofthe apron 26, and is journal mounted on the supporting frame 23. Thisshaft 46 is driven through a clutch 50 from a suitable power source suchas the motor 52 having a variable speed control handle 54. Secured tothe shaft 46 at various apparently random, but predetermined locationsalong the axial length thereof are a number of mounting blocks 56, eachof which carries on the outer or peripheral portions thereof one or moredamming shoes 58. So that the angular position of each block 56 as wellas its longitudinal position along the length of the shaft 46 can beadjusted, each block 56 is fixed to the shaft 46 by means of arespective hold screw 60.

Each shoe 58 is made of a flexible material and is secured by itsleading edge 62 to its related block 56. That peripheral surface portionor portions 64 of each block 56 which backs its respective one or moreshoes 58 is curved along an are having the axis of the drive shaft 46 asits center of curvature. The shaft 46 and the blocks 56 with their shoes58 are so located with respect to the apron 26 that as the shaft 46rotates (clockwise as seen in FIGURE 2), each shoe 58, as it passes thedischarge edge 28 of the apron 26 engages with moderate pressure thisdischarge edge 28. With the shaft 46 being located above and moderatelyforward of the discharge edge 28, the exposed or contact surface 66 ofeach shoe 58, while contacting the discharge edge 28, makes an angle ofabout ten to twenty degrees with the surface of the apron 26. The effectof each shoe 58 so contacting the apron 26 is to interrupt the flow ofliquid off the apron 26 at the area of contact and to actually back upor dam the liquid on the apron immediately behind the shoe 58 which isso contacting the apron 26. When the trailing edge 68 of the shoe liftsfree of the discharge edge 28 of the apron 26, this dammed oraccumulated liquid flows over the discharge edge 28 in a surge of flowso that a concentrated puddle falls on the panel 12 passing beneath.

After this surge of flow, the liquid flows over this now unobstructedportion of the discharge edge 28 at a more moderate rate. By properlycontrolling the rate of liquid flow from the pumps 49a, b, and c, thismore moderate rate of liquid flow over the discharge edge 28 will besuch that the liquid breaks off in random and discontinuous drops andstreaks, which fall onto the panel 12. Also, at locations along theapron edge 28 where no shoes 58 make contact, the flow will continuouslybe in random streaks or drops.

It is readily apparent that the width (dimension parallel to axis of thedrive shaft 46) and length (i.e. arc length) of each of these shoes 58may be varied, and that several shoes 58 may be placed on one block soas to be at the same location along the length of the shaft 58. Inaddition, these various shoes 58 may be shifted both longitudinally andangularly and may be reap-ranged on the shaft '58 so that a greatvariety of patterns of these concentrations of the liquid material ofthe discontinuous applications may be achieved.

After each complete revolution of the shaft 58, the shoes 58 willsubstantially repeat the distribution of the various concentration ofmaterial on the panels 12. ever, not only will there be some moderatevariation in these various corresponding concentrations of material fromone revolution of the shaft 58 to the next, but the discontinuous andrandom flow of the liquid over areas of the discharge edge 28 which arenot being obstructed by the shoes 58 will not necessarily follow anypattern dictated by the various surges of liquid flow caused by thedamming action of the shoes 58. Hence, while an overall pattern doesprevail by virtue of the predetermined concentrations of flow, therewill be in each location of Howeach panel distinctive variations notexisting in the corresponding location of any other portion of anypanel.

It will be noted that the front top edges 44b and 44c of the middle andrear trough 24b and 240 are formed with a plurality of randomly spacedshallow (i.e. one quarter of an inch or less) cut-outs 70 of varyinglength (i.e. the dimension parallel to the edge 4412 or c). The elfect,of this is to localize or direct the liquid from the related trough 24bor 0 along definite channels onto their respective drip aprons 45b or cand then onto the liquid in the adjacent forward trough 24a or b. Thereis random flow over the portions of the edges 44b and c not so notchedso that the three separate sources of liquid mix to some extent in themiddle and front troughs 24b and a, but where the liquid fiows through acut-out 70, it maintains substantial identity or separation. By properlyarranging the various cut-outs 70 in relation to the arrangement ofdamming shoes 58, various concentrations predominantly of one of thethree different liquids can be produced. Or if desired, concentrationsof the discontinuous coat in which two or three of the liquid sourcesare substantially present may be achieved.

By varying the relative rates of flow into the three troughs 24a, b, andc, one or two of the sources of liquid of the discontinuous coat may bemade to predominate in the pattern of the panels 12. By increasing ordecreasing the total flow over the discharge end 28, the amount ofdiscontinuous and random flow over the unobstructed portions of thedischarge end 28 may be changed, so as to vary the non-repetitive orrandom deposits of the material of the second coating, and the amount ofliquid in the various surges or concentrations can also be varied.

What is claimed:

1. An apparatus to app-1y liquid in a discontinuous manner onto asubstrate member, said apparatus comprising: a liquid dispensing apronhaving an elongate discharge portion over which liquid is dispensed ontosaid substrate member, means to feed said liquid onto said apron at apredetermined rate with a predetermined distribution on the apron, meansto periodically obstruct and then release liquid flow at said dischargeportion at predetermined time intervals and at various predeterminedlocations at said discharge portion, so that when flow is so interruptedby said obstructing means at any one of said locations, liquid collectsat said any one of said locations during such interruption, and uponrelease of collected liquid at said any one location, there is aconcentration of liquid flow from said any one location onto saidsubstrate member.

2. The apparatus as recited in claim 1, wherein said obstructing meanscomprises a plurality of shoe members each of which engages said apronat periodic interva-ls.

3. The apparatus as recited in claim 2, wherein said shoe members areadjustably mounted 'for circular motion about a rotary axis.

4. The apparatus as recited in claim 2, wherein said shoe members areflexible and are arranged to yieldingly engage an edge of said apron atthe discharge portion thereof.

5. The apparatus as recited in claim 2, wherein said shoe members eachpresent a generally planar obstructing surface, which surface when it isadjacent said discharge portion, makes with the surface portion of saidapron from which said fluid is discharged an angle less than forty fivedegrees.

6. The apparatus as recited in claim 1, wherein said feed meanscomprises a trough having a weir over which liquid flows onto saidapron.

7. The apparatus as recited in claim 6, wherein there are a plurality ofsaid troughs arranged for series flow onto said apron, each of saidtroughs being arranged to contain a liquid of a particular character sothat flow from one trough to another and finally onto said apron causesa how onto said substrate member of liquid of varying characteristics.

8. The apparatus as recited in claim 7, wherein at least one of saidtroughs has a weir, portions of which are of different elevation so thatflow from said one trough over its weir is lacking in uniformity ofdistribution.

9. The apparatus as recited in claim 8, wherein said one trough isdisposed for the liquid therefrom to flow into a second trough andfinally onto said apron, whereby the liquid from said one and saidsecond troughs maintains a fair degree of identity as it flows over theapron and onto said substrate member.

10. The apparatus as recited in claim 7, wherein the troughs are soarranged that when a first liquid flows from. one trough onto a secondliquid in a following trough, the first liquid drops a moderatedistance, so that there is little intermixing of said first and secondliquids.

11. The apparatus as recited in claim 6, wherein at least one of saidtroughs is mounted for swing motion about an axis parallel to the lengthof the trough.

12. The apparatus as recited in claim 1, wherein the discharge portionof said apron comprises a substantially continuous horizontal edge sothat moderate liquid flow over said apron will, when unobstructed, be inrandom paths over said discharge edge, and when obstructed, will be insurges of a predetermined character.

13. An apparatus to apply liquid in a discontinuous manner onto asubstrate member, said apparatus comprising: a liquid dispensing apronhaving an elongate discharge portion over which liquid is dispensed ontosaid substrate member, means to feed said liquid onto said apron at apredetermined rate with a predetermined distribution on the apron, meansto periodically obstruct and then release liquid flow at said dischargeportion at predetermined time intervals and at various predeterminedlocations at said discharge port-ion, so that when flow is sointerrupted by said obstructing means at any one of said locations,liquid collects at said any one of said locations during suchinterruption, and upon release of collected liquid at said any onelocation, there is a concentration of liquid flow from said any onelocation onto said substrate member, means to move said substratemember, relative to said apron at a predetermined rate and along a pathhaving a component perpendicular to a general line of elongation of saiddischarge port-ion, whereby said liquid is distributed onto saidsubstrate member in a suitable manner.

14. A method to apply liquid in a discontinuous manner onto a substratemember, said process comprising:

(a) feeding said liquid onto a discharge apron at a predetermined rateand with .a predetermined distribution so that said liquid flows over adischarge portion of said apron,

(b) periodically obstructing and then releasing flow over said dischargeportion at predetermined time intervals and at predetermined locations,so that when flow is so interrupted at any one of said locations, liquidcollects at said any one location during such interruption, and uponrelease of the collected liquid, there is a surge of liquid flow at saidany one location, and

(c) moving said substrate member beneath said apron so that liquid flowsonto said substrate member in a desired general pattern.

15. The method as recited in claim 14, wherein said predetermined rateof liquid flow is sufficiently moderate so that the flow over saiddischarge portion, aside from said surges, is irregular anddiscontinuous.

16. The method as recite-d in claim 14, wherein said liquid comprisesseveral liquid portions having differing characteristics, and oneportion of said liquid is fed onto said other portion with an irregulardistribution so that 7 8 the liquid portions fed onto said apronmaintain a fair References Cited by the Examiner of identity with agenerally predetermined dis- UNITED STATES PATENTS n u 10!]. i .17. Themethod as recited in claim 14, wherein said ggfi ggfl substrate memberis initially coated with a first layer 5 2761419 9/1956 Merger et ofliquid which forms a friable film, with the result that w hen liquid isapplied in a discontinuous manner onto FOREIGN PATENTS said substratemember, said discontinuously applied liquid 191,007 8/ 1964 Sweden.

breaks through said friable film as concentrations of saiddiscontinuously applied liquid flow over said apron onto 10 ALFREDLEAVITT, y Examine!- aid s rate member. E. B. LIPSCOMB, AssistantExaminer.

13. AN APPARATUS TO APPLY LIQUID IN A DISCONTINUOUS MANNER ONTO ASUBSTRATE MEMBER, SAID APPARATUS COMPRISING: A LIQUID DISPENSING APRONHAVING AN ELONGATE DISCHARGE PORTION OVER WHICH LIQUID IS DISPENSED ONTOSAID SUBSTRATE MEMBER, MEANS TO FEED SAID LIQUID ONTO SAID APRON AT APREDETERMINED RATE WITH A PREDETERMINED DISTRIBUTION ON THE APRON, MEANSTO PERIODICALLY OBSTRUCT AND THEN RELEASE LIQUID FLOW AT SAID DISCHARGEPORTION AT PREDETERMINED TIME INTERVALS AND AT VARIOUS PREDETERMINEDLOCATIONS AT SAID DISCHARGE PORTION, SO THAT WHEN FLOW IS SO INTERRUPTEDBY SAID OBSTRUCTTNG MEANS AT ANY OE OF SAID LOCATIONS, LIQUID COLLECTSAT SAID ANY ONE OF SAID LOCATIONS DURING SUCH INTERRUPTION, AND UPOMRELEASE OF COLLECTED LIQUID AT SAID ANY ONE LOCATION, THERE IS ACONCENTRATION OF LIQUID FLOW FROM SAID ANY ONE LOCATION ONTO SAIDSUBSTRATE MEMBER, MEANS TO MOVE SAID SUBSTRATE MEMBER, RELATIVE TO SAIDAPRON AT A PREDETERMINED RATE AND ALONG A PATH HAVING A COMPONENTPERPENDICULAR TO A GENERAL LINE OF ELONGATION OF SAID DISCHARGE PORTION,WHEREBY SAID LIQUID IS DISTRIBUTED ONTO SAID SUBSTRATE MEMBER IN ASUITABLE MANNER.
 14. A METHOD TO APPLY LIQUID IN A DISCONTINUOUS MANNERONTO A SUBSTRATE MEMBER, SAID PROCESS COMPRISING: (A) FEEDING SAIDLIQUID ONTO A DISCHARGE APRON AT A PREDETERMINED RATE AND WITH APREDETERMINED DISTRIBUTION SO THAT SAID LIQUID FLOWS OVER A DISCHARGEPORTION OF SAID APRON, (B) PERIODICALLY OBSTRUCTING AND THEN RELEASINGFLOW OVER SAID DISCHARGE PORTION AT PREDETERMINED TIME INTERVALS AND ATPREDETERMINED LOCATIONS, SO THAT WHEN FLOW IS OS INTERRUPTED AT ANY ONEOF SAID LOCATIONS, LIQUID COLLECTS SAID ANY ONE LOCATION DURING SUCHINTERRUPTION, AND UPON RELEASE OF THE COLLECTED LIQUID THERE IS A SURGEOF LIQUID FLOW AT SAID ANY ONE LOCATION, AND (C) MOVING SAID SUBSTRATEMEMBER BENEATH SAID APRON SO THAT LIQUID FLOWS ONTO SAID SUBSTRATEMEMBER IN A DESIRED GENERAL PATTERN.